Installing windows gets stuck

Hi,

I recently brought a 'Dell Poweredge 1850' it has 2x 73Gb HDD, I have tried to install 'Windows server 2008' (Not R2) however, when I go to install the OS it will freeze on copying windows files it will usually stop at '55%' I have no idea why this happens, I have downloaded the copy from Microsoft website so it isn't pirated ect, I have configured RAID correctly with RAID 0. Can somebody please point out why this isn't working!

Thanks!!